High speed web stopping mechanism



P. E. FISCHER METAL 3,085,457

HIGH SPEED WEB STOPPING MECHANISM April 16, 1963 FiledMaroh 11, 1960 Q QQ Q m .3 v 3 6 Sheets-Sheet 1 INVENTORS. PAUL E. FISCHER HERBERT E. NEHBY z A TORNEYS April 16, 1963 P. E. FISCHER ETAL HIGH SPEED WEB STOPPINGMECHANISM Filed March 11, 1960 6 Sheets-Sheet 2 INVENTORS. PAUL 1:.FISCHER HERBER T E. NE/T A TOR/VEYS' FIG. 8

April 16, 1963 Filed March 11. 1960 P. E. FISCHER ETAL HTGH SPEED WEBSTOPPING MECHANISM 6 Sheets-sheaf 3 INVENTORS.

PAUL E. FISCHER HERBERT E. NEFF P. E. FISCHER ETAL 3,085,457

HIGH SPEED WEB STOPPING MECHANISM April 16, 1963 6 Sheets-Sheet 4 FiledMarch 11. 1960 A TOR/VEVS' April 16, 1963 P. E. FISCHER ETAL HIGH SPEEDWEB STOPPING MECHANISM 6 Sheets-Sheet 5 JNVENTORS PAUL E FISCHEQ HERBERTE. A/E/T Filed March 11, 1960 ATTORNiVJ A ril 16, 1963 P. E. FISCHERETAL HIGH SPEED WEB STOPPING MECHANISM e Sheets-Sheet 6 Filed March ll,1960 s r m RRH mm m VF T N R 1.55 w M M United States Patent 3,085,457HIGH SPEED WEB STGFPIIJG MECHANISM Paul E. Fischer and Herbert E. Naif,Short Hills, NJ assignors to Champlain Company, Inc., Roseland, N.J., acorporation of New York Filed Mar. 11, 196i), Ser. No. 14,314 2 Claims.(Cl. 83-236) This invention relates to web stopping mechanism forrepeatedly and cyclically stopping one part of an otherwise continuouslytravelling web, typically for use with a punch press, and relates moreparticularly to such mechanism intended to operate at high speed.

Such a punch press may follow other machines (for example, a printingpress line) through which the web travels at uniform speed. A pawl andratchet or a Geneva drive may be used at slow speeds, but cannot operateat high speed. Presses have been devised with a swinging punch whichmoves along with the web, but this requires movement back and forth of agreat mass. Special cam-operated accelerating drives have been providedto alternately speed and stop the web, but such accelerating drives arecomplex and require reversal of reciprocating parts.

Another system has been devised in which the web is reversely loopedbefore and after the punch press, and is fed by feed rollers which turnat uniform speed but which are physically moved back and forth. Theforward movement accelerates the web, and the backward movementcounteracts the forward feed thereby stopping the web. This system hasadvantages but still requires reversal of reciprocating parts.

The primary object of the present invention is to improve such a webstopping mechanism. A further object is to provide mechanism in whichthe parts rotate rather than reciprocate, thereby making it easy tobalance the same. Still another object is to provide the mechanism witha web feed unit ahead of the mechanism and a web pull unit following themechanism which are stationarily mounted and geared together for equalspeed. If, as is usually the case, the punch is to be registered withprinted matter already on the web, an electric eye scanning system maybe employed to slightly advance or retard feed and pull units tomaintain the desired registration.

The web stopping mechanism and the punch press mechanism preferablyemploy a common drive so as to maintain synchronism therebetween.However, the pitch length along the web may vary from one job toanother, and this presents the problem of changing the stop intervalproduced by the web stopping mechanism. Accordingly, a further object isto facilitate change or adjustment of the pitch length.

To accomplish the foregoing general objects, and other more specificobjects which will hereinafter appear, the invention resides in thepunch press and web stopping mechanisms and the relation of one to theother as are hereinafter more particularly described in the followingspecification. The specification is accompanied by drawings in which:

FIGURE -1 is a front elevation of punch press and web stopping mechanismembodying features of the invention;

FIGURES 2, 3, 4 and 5 are explanatory of the invention;

FIGURE 6 is explanatory of a part of the web feed mechanism;

FIGURE 7 is a front elevation of another embodiment ol the inventionwhich adds some refinements;

FIGURE 8 is a transverse vertical section taken approximately in theplane of the line 8- 0 of FIGURE 7;

FIGURE 9 is a horizontal section taken approximately in the plane of theline 9-9 of FIGURE 7;

FIGURE 10 is a transverse vertical section taken approximately in theplane of the line 10-10 of FIG- URE 7;

FIGURE 11 is a view drawn to enlarged scale and shows means forsimultaneously adjusting the eccentricity of a loop-forming roller andits counter-Weight;

FIGURE 12 is a top view of the same;

FIGURE 13 shows a change gear and feathering drive mechanism used in themachine here described;

FIGURES 14 and 15 are explanatory of some details; and

FIGURE 16 shows a modification for handling sheets.

Referring to the drawing and more particularly to FIGURE 1, the webstopping mechanism serves to alternately stop and accelerate a portion12 of a continuously fed web 14, the portion 12 being at a station Wherethe web is to be operated on, in this case by a punch press generallydesignated P. The web stopping mechanism comprises a first idle rolleror idler 16 forming a reverse loop of web 18 ahead of the station P, andanother idler 20 forming a second similar reverse loop of web 22following the station P. A shaft 24 carries the idler 16 ec-centrically,and a shaft 26 similarly carries the idler 2d eccentrically.

These shafts are geared together for continuous and equal rotation, inthis case by means of a train of gears including gear 28 on shaft 26, anidle gear 30, gear 32 on the punch press crank shaft 34, idle gear 36,and gear 38 on shaft 24. The gears are equal, or if not, aresymmetrically arranged so that shafts 24 and 26 turn equally. However,the eccentric or crank mounting of the loop forming idlers 16- and 20"is so oriented that they are apart or opposite in phase. This is done sothat one of the loops 18, 22 is lengthened while the other is shortened.The idlers 16 and 20 have the same radius of eccentricity, and theradius is so selected that the portion 12 of the web is stopped atdesired intervals or pitch length.

The action may be explained with reference to FIG- URES 2, 3, 4 and 5 ofthe drawing, which show idler 16 revolving eccentrically on shafit 24.In FIGURE 2 the loop 18 is of intermediate length. In FIGURE 3, withroller 16 down, the loop 18 has its maximum length. In FIGURE 4 the loopagain has an intermediate length, the same as that shown in FIGURE 2. InFIGURE 5 with the roller in its up position the loop 18 has its minimumlength. Inasmuch as the other idler rotates in opposite phase, the loop22 (FIGURE 1) is long when the loop 18 is short, and vice versa.

The maximum rate of change of loop length takes place in mid-position asshown in FIGURES 2 and 4. When loop 18 is rapidly shortening as shown inFIGURE 4, the web portion 12 has been accelerated and is moving fasterthan the main web 14. When loop 18 is rapidly lengthening, as shown inFIGURE 2, the web portion 12 is decelenated because the loop motion isopposite to the normal web travel at 14, and the parts are properlydimensioned so that the backward motion equals the forward motion, andthe web portion 12 is stationary for an instant.

Considering the arrangement in somewhat greater detail, the mechanismpreferably includes a continuous web feed unit 40 ahead of the press P,and a continuous web pull unit 42 following the press. The feed and pullunits are geared together, as by means of miter gears 44 (FIGURES l and6), shaft 46, and miter gears 48 which interconnect the feed units forequal continuous web feed. The lower feed rollers 41 and 43 arepositively driven, and the upper rollers act as pressure rollers.

The punch press P has a main shaft 34, preferably located near thebottom of the press. The stationary bolster of the press carries -alower die, while the upper die is mounted on a vertically reciprocablehead or bolster 50. This is guided by guide rods 52, and is reciprocatedconnecting rods 54 on opposite sides of the press. The lower ends of theconnecting rods lead to cranks shown at 56, and preferablycounterbalanced by counterweights 58.

The idlers 16 and 20 are preferably located near the bottom of the pressso that they form generally upright loops 18 and 22. The revolvingidlers are counterbalanced by approp-riate counter-weights indicated at60 and 62. This counter-balance is easy to accomplish because the idlersare rotating at uniform speed in one direction, there being no reversalor reciprocation. To help form the loops .18 and 22, there areadditional guide rollers 64 and 66 at opposite ends of the press.

The machine is here shown using a pre-printed Web, that is, one whichhas been printed and rolled up, so that the web 14 is being fed from apaper roll 70. This is mounted at 72, and may be equipped with the usualautomatic brake and side guide controls, not shown. Arm 73 may sense thediameter of the roll for automatic bnake control.

The Web is taken up on a roll 74 mounted on a rewind stand at 76. Thishas its own rewind drive motor, which may 'be conventional and is notshown. The 'web leaving the pull unit 42 may, if desired, be slit priorto rewinding and a 'slitter for this purpose is shown at 78.

In order to register the printed web 14 with the punch action, anelectric scanning head may be provided as shown at 80, and this senses aregister mark on the web, and then feeds any necessary correction to thefeed and pull units. This is shown in FIGURE 6 in which the feed rollers41 and-43 are connected by miter gearing. The scanning head 80 operatesa correction motor 82 in one direction or the other, and this feeds someextra motion into change gear box 84 through differential gearing indifferential register mechanism 86. The input shaft 88 of the changegear box either receives the main drive, or is connected to the mainshafts of the punch press. By changing the gears in thechange gear box,the proper repeat length or pitch length of web may be supplied for eachpunch stroke. Substantially the correct ratio is provided, but slightcumulative error may be corrected by the photo-cell scanner 80controlling correction motor 82. The drive maybe refined by use of aninfinitely variable drive unit with automatic ratio correction, asdescribed in U.S. Patent 2,812,938 issued November '12, 1957.

It will be understood that for continuous operation the simple rollerstands here shown at 72 (FIGURE 1) and 76, or more usually the latter,may be replaced by more elaborate stands carrying multiple paper rollswhich facilitate roll change. Moreover, if the punch press follows aprinting press line, the roller stand at 72 iseliminated entirely, andthe input shaft 88 (FIGURE 6) is connected to both the punch press andthe printing press line.

.A modified form of the invention which embodies some additionalimprovements may be described with reference to FIGURES 7 through 13 ofthe drawing.

Referring first to FIGURE 7, a continuously moving web 90 is fed by acontinuous feed roller92. A first eccentric idler 94 forms a generallyupright loop 96 ahead of the die 100. A second eccentric idler 102 formsanother generally upright loop 104 following the die 100'. The web thengoes to a pull roller 106. The pressure roller 108 for feed roller 92and the pressure roller :110 for pull roller 106 are mounted on arms 112pivoted at 114 and spring pressed by means of compression springs 116.The pressure may be relieved 'by rods 118 connected to eccentrics onshafts 120 which may be turned by handles 122. These may be swung fromthe on 4 position shown at lock 124 to an off position indicated at lock126, thereby releasing the pressure rollers to facilitate threading of aweb through the machine.

The main shaft of the punch press is shown at 128. This carrieseccentrics 130 and connecting rods 132 extending upward to the upperhead or bolster 134 of the punch press.

Referring now to FIGURE 10, the main shaft 128 with its eccentrics 130and connecting rods 132 is connected to pins 136, and through them tothe bolster 134'. This carries the upper die while the lower die 101 ismounted on the lower bolster 14 0 of the punch press.

The eccentrics and also the mass of the connecting rods and head, arepartly counter-balanced by means of counter-weights 142 secured to mainshaft 128. They are additionally counter-balanced by gears 144 and 150which are cut away at 145 and 151. Any residual unbalance in the punchpress is vertical, and inertia force in that direction is less importantbecause it may be transmitted directly to the floor. The other motionsmay be completely balanced because they are rotative motions.

The main shaft 128 carries a gear 144. This is not shown in FIGURE 7,but constitutes the middle gear of a gear train like that marked 28, 30,3-2, 36 and 38 in FIGURE 1, the gear 144 in FIGURE 10 corresponding tothe gear 3 2 in FIGURE 1. It is preferred to make the machinesymmetrical and to drive both ends of the eccentric rollers so that theycan be crank mounted, and in FIGURE 10 there is a similar spur gear onthe opposite side of the press. This again forms the mid gear of a trainof five gears, the end ones of which serve to turn the eccentricrollers.

The main shaft 128 carries a flywheel 146. If the web is supplied from aroll, as shown in FIGURE 1, the main drive may be belted directly to theflywheel 146, its periphery being grooved with multiple V grooves 148 toreceive a multiple V belt drive.

The main shaft 128 further carries a bevel gear 152 for use when thedrive goes also to a printing press line. The troughs 156 and ducts 158are connected to suitable suction, means for the removal of the scrap orwaste punched-from the web by the die.

Referring now to FIGURE 8, which is a vertical section through theeccentric roller 102 following the die, the roller is freely rotatableon a shaft 160' carried by cranks 162. The crank shafts 164, 165, run inbearings carried by the main side frames 166 of the machine. Shaft 164is turned by a gear 168 which corresponds to gear 28 in FIGURE 1. Shaft165 is turned by a gear which constitutes the corresponding end gear ofthe matching gear train on the opposite side of the machine. Tofacilitate timing of the eccentric rollers, the gears 168 and 170 areadjustable (by means of bolts 172) relative to the hubs 174, which arekeyed to the shafts 164, 165. For fine adjustment, oppositely rotatableset screws 176 (FIGURES 8 and 14) may be employed, these fitting onopposite sides of bolts 172 as is better shown in FIGURE 14.

The radius or throw of eccentric roller 102 is preferably madeadjustable, and for this purpose the cranks 162 have radially movableslides 178 which carry the shaft 160. The position of a slide isadjustable by means of a radially disposed screw 180. The roller 102 iscounter-balancedby means of counter-weights 182, and the throw of theseweights is changed when the throw of the roller is changed. This ispreferably accomplished by the same screw 180' which, for that purpose,is given left hand and right hand thread portions.

This mechanism is better shown in FIGURES 11 and 12, referring to whichthe roller shaft is carried in a split hearing or holder 184. This formsa part of slide 178 which is radially adjustable on crank 162 by meansof slots 186 through which the fastening bolts 188 pass. In somewhatsimilar fashion, the counter-Weight 182 is radially adjustable bymeansof bolts 190 passing through slots 192. The screw 180 has a square endto receive a wrench, and a left hand thread portion 194 engages slide178 while a right hand thread portion 196 engages counterweight 182. Thescrew 180 is itself held against axial movement by an integral collar198. It Will be evident that by loosening the bolts 188 and 190 andturning the screw 180, the eccentric roller and its counterweight aremoved toward or away from the axis of shaft 164, and when these partshave been moved the desired amount, the bolts 188 and 190 are againtightened. FIGURE 12 shows how the slidable parts may be additionallyfitted together with a tongue and groove relation as shown at 200.

If the counter-weights are lighter than the idler but are used at alarger radius, the pitch of the LH and RH threads will differcorrespondingly. In the particular case shown the LH thread is sixteento the inch and the RH thread is ten to the inch, so that the ratio oftravel is 8 to 5, the counter-weights having an effective mass of /8that of the idler being balanced.

Referring now to FIGURE 9, feed roller 92 and pull roller 106 are gearedtogether as previously described, there being bevel gears at 202 leadingto shaft 154, the other end of which has bevel gearing 204 leading topull roller 106. The shaft of the pull roller is extended at 206 toreceive the input or drive. In FIGURE 9, shaft 206 is driven by asuitable registering drive including a change gear box shownschematically at 214, and corresponding to box 84 in FIGURE 6. The inputto the registering drive is from shaft 212 driven by pulley 146 andshaft 128. FIGURE 8 shows shafts 212 and 20-6 but omits the change gearbox. The bevel gear 152 on the main shaft 128 of the punch press mesheswith a bevel gear 208 carried on a shaft 210. This is horizontal, andruns longitudinally of the press line. It is connected to the main linedrive shaft when the present device follows a printing press line orother machinery operating on the web. The punch drives the printingpress.

Referring now to FIGURE 13, the input and output shafts are shown at 212and 206 respectively. Box 214 houses change gears and a differentialunit. The change gears usually include compound gearing, but forsimplicity the gear train here shown simply has gear 215, 216, and 217driving gear 218 which leads into the bevel gear 219 (FIGURE 15) of adifferential. The spider and gear cluster or planet bevel gears 220 arecarried by the output shaft 206 previously described. The opposite bevelgear 221 is secured to a worm gear 222, which is also shown in FIGURE13. This feeds in corrective motion.

To make gear selection less critical, an infinitely variable drive 223is employed. This is driven by bevel gearing 224 and timing belt 225.Disregarding differential 226, the output goes through timing belt 227to worm 228 and worm gear 222. The ratio in unit 223 is shown variedmanually by a hand wheel 231. In effect, the change gear box is madeinfinitely variable within the designed range. The drive 223 may be aGraham drive.

In addition there is an electric eye scanning correction for print topunch registration. The scanning head is shown at 229 in FIGURE 7. Itleads to suitable electronic circuitry, and then to a correction motor230 (FIG. '13) which is reversible and which feeds motion to thedifferential unit 226, thereby advancing or retarding the rate of travelof timing belt 227, to maintain print to punch registration.

As an additional refinement, hand wheel 231 may itself be replaced by acorrection motor, controlled as taught in US. Patent 2,812,938,previously referred to.

One refinement in the present machine is the provision of means tocompensate for angularity of the loops. Referring to FIGURES 2-5 it willbe seen that in FIGURES 3 and 5 the loop is upright, but in FIGURE 2 theloop has been moved somewhat to the right, and in FIGURE 4 it has beenmoved somewhat to the left. In many cases the difference in web lengthresulting from this angularity was found to be negligible. With a largeeccentricity it may become noticeable. It may be compensated, ifdesired, as for example when dealing with exceptionally delicatematerials. Referring to FIGURE 7, the guide rollers 236 and 238, insteadof being idle, may be positively driven, and may be slightlyeccentrically mounted in such a manner as to compensate for theaforesaid angularity.

Referring now to FIGURE 8, the roller 238 is fixed on a shaft 240carrying a sprocket gear 242. This is driven by a sprocket gear 244mounted on loop-forming roller shaft 164, it being understood that asprocket chain 246 extends between gears 242 and 244, the chain beingkept taut by an adjustable idle sprocket 248. The gear ratio is 2 to 1,so that angularity is compensated twice in each revolution of the roller102, as it should be. This chain drive is also shown in FIGURE 7 at 246.

The other compensating roller 236 (FIGURE 7) could be driven in similarfashion from the shaft of the eccentric roller ahead of the die.However, in the present case the second compensating roller 236 isdriven from the first compensating roller 238, and this is done throughhelical gears 250 (FIGURE 9) driving a shaft 252 which in turn driveshelical gears 254 leading to the shaft 256 of compensating roller 236.At roller 238 the upper helical gear is shown, and at roller 236, theupper helical gear is broken away to show the lower helical gear. Someof these parts are more clearly shown in FIGURE 8, referring to which,shaft 240 carries a helical gear 250 meshing with a helical gear 251 onshaft 252. This shaft 252 is also shown in FIGURE 10. The compensatingrollers are driven in one to one ratio.

' FIGURE 1 shows a different form of drive for the compensating rollers.In this case a chain 260 runs in a generally triangular path, and isdriven by a drive sprocket wheel 262 on idle gear 30. It engagessprocket wheels on the shafts of guide rollers 64 and 66. These havehalf the diameter of sprocket wheel 262. It will be understood thatrollers 64 and 66 are eccentrically mounted when being used forcompensation, and not when angularity of the loops is being disregarded.The rollers in both forms turn freely on their driven eccentric shafts.

So far the use of a web rather than sheets has been described. However,the web may be replaced by endless conveyor chains or belts carryingpushers or grippers for handling sheets. Referring to FIGURE 16, thepunch 280, the eccentric idlers 282 and 284, the drive sprocket wheel286 or 288, and the idle sprockets 290 and 292, all correspond tosimilar parts previously described. The idlers 282 and 284 formgenerally upright loops, as shown. As before, idlers 282 and 284, andpunch shaft 294 are driven together, and idlers 236 or/ and 288 are,driven in proper speedratio. The conveyor chains are indicated at 296,and have pushers (or grippers) 298 for feeding sheets from a stack 300(or from a supply belt) to station 280, and thence to delivery todelivery belts 302, with stacking at 304 if desired. Chain slack may betaken up at 306 or at 308 or both,'as by the use of springs as shown, orair cylinders, or the like. No scanning mechanism is needed.

The sides of the loop may be kept parallel, instead of convergent asshown in FIGURES 1 and 7. In fact this is preferable when room isavailable for appropriate spacing between the upper rollers which helpform the upper end of the loop.

It is believed that the construction and operation of our improved Webstopping mechanism, as well as the advantages thereof, will be apparentfrom the foregoing detailed description.

It will be understood that the web may be paper, paper backed foil,cardboard, cellophane, cellulose acetate or other plastic films, and soon. The web may be roll fed, as shown in FIGURE 1, or it may come fromother machines, typically a printing press line. The punch press may beused to perforate, notch, score, or crease.

Moreover, the station at which the Web is cyclically stopped may servesome other and wholly different purpose, as for example, the loading ofsmall hardware parts or food products, etc. on to a web where the partsare enclosed by another web or by individual pockets.

Except for the vertical motion of the punch press, all of the motionsare rotary and therefore are readily b-alanced. The vertical inertialforce of the punch press is partially counter-balanced, and any residualis applied to the floor mounting which may be made suitably heavy. Thepunch press itself may be of an improved type which is fully balanced.

The crank throw is surprisingly small. If the blank or pitch length is,say, d2 inches, the motion needed is that divided by pi, or less than 4inches, and this is divided by two because each loop has a descending aswell as ascending web portion, and the result is again divided by two,thus computing a radius of less than one inch for a 12 inch blank. Thispitch length is varied by adjustment of the eccentricity or throw of theroller, and its counter-weights are correspondingly adjusted to maintainbalance.

The error caused by angularity of the loop is very small and far lesssignificant than the advantage gained by continuous unidirectionalrotary motion of the eccentric rollers. In most cases it may bedisregarded, but even this small roller may be compensated, as bydriving the shafts of slightly eccentrically mounted rollers. The guiderollers at the upper ends of the loops may be altered for this purpose.The angularity error is minimized by lengthening the loop, but itispreferred to keep this within reasonable limits, in order to stay wellabove floor level.

It will be understood that the loops need not be upright, although thatdisposition is preferred in order to save floor space. The eccentricrollers are preferably made of light weight metal and are preferablyhollow to reduce their mass.

Although the loop varying rollers have been shown as idlers which arerevolved eccentrically by a drive shaft, they may be made non-rotatableand given a polished surface for web slippage.

It will be understood that while we have shown and described ourinvention in several preferred forms, changes may be made in thestructures shown without departing from the scope of the invention assought to be defined in the following claims. In the claims thereference to the loop forming roller :as an idler is not intended toexclude the use of a paper guide with web slippage rather than anidler.Inthe claims the term web is not intended to exclude a chain or beltdriving pushers or grippers which move sheet-s which are to be operatedon at a station.

We claim:

1. Web punching mechanism for operating on a continuously fed web, saidmechanism comprising avertically reciprocable punch press and dierequiring an intermitteut web feed, and means for alternately stoppingand accelerating that portion of the web which is in the die, said meansincluding a first idler near the bottom of the press cooperating withtwo collateral spaced directionchanging rollers thereabove at the dieheight to form a generally upright reverse loop of web ahead of the die,said idler being located in and forming the lower end of the loop, asecond similar idler near the bottom of the press cooperating with twocollateral spaced direction-changing rollers thereabove at the dieheight to form a second similar generally upright reverse loop of webfollowing the die, the sides of the said loops being approximatelyparallel, and having a vertical dimension which is large relative to theeccentricity in order to minimize the problem of angularity as the loopis oscillated by the idler, a shaft carrying said first idlereccentrically, a shaft carrying said second idler eccentrically, meansgearing said shafts together for continuous equal rotation in oppositephase so that one loop is lengthened while the other is shortened, saididlers having the same radius of eccentricity so selected that the webis stopped at desired pitch length, gearing for driving'one of saiddirection-changing rollers ahead of the die and one following the die intwoto-one ratio relative to the rotation of the shafts carrying theeccentric loop-forming rollers, the said driven direction-changingrollers being slightly eccentrically mounted, the amount of eccentricityand the phase relation of the said driven direction-changing rollersbeing such as to compensate for the angularity of the loops causedduring revolution of the eccentric loop-forming idlers.

2. Web punching mechanism for operating on a continuously fed web, saidmechanism comprising a vertically reciprocable punch press and dierequiring an intermittent web feed, a main shaft near the bottom of thepress for driving the same, said main shaft extending transversely ofthe direction of travel of the Web, and means for alternately stoppingand accelerating that portion of the web which is in the die, said meansincluding a first idler near the bottom of the press cooperating withcollateral spaced direction-changing rollers thereabove at the dieheight to form a generally upright reverse loop of web ahead of the die,said idler being located in and forming the lower end of the loop, asecond similar idler near the bottom of the press cooperating with twocollateral spaced direction-changing rollers thereabove at the dieheight to form a second similar generally upright reverse loop of webfollowing the die, the sides of the said loop being approximatelyparallel, and having a vertical dimension which is large relative to theeccentricity in order to minimize the problem of angularity as the loopis oscillated by the idler, a shaft parallel to the main shaft andcarrying said first idler eccentrically, a shaft parallel to the mainshaft and carrying said second idler eccentrically, means gearing saidshafts together for continuous equal rotation in opposite phase so thatone loop is lengthened while the other isshortened, means gearing saididler shafts to saidmain shaft in one-to-one ratio and in such phasethat the first'loop is lengthening and the second is shortening atmaximum rate when the die is closed, said idlers having the same radiusof eccentricity so selected that the web is stopped at desired pitchlength, gearing for driving one of said direction-changing rollers aheadof the die and one following the die in two-to-one ratio relative to therotation of the shafts carrying the eccentric loop-forming rollers, thesaid driven direction-changing rollers being slightly eccentricallymounted, the amount of eccentricity and the phase relation of the saiddriven direction-changing rollers being such as to compensate for theangularity of the loops caused during revolution of the eccentricloop-forming idlers.

References Cited in the file of this patent UNITED STATES PATENTS938,452 Ball Oct. 26, 1909 969,418 Staude Sept. 6, 1910 1,679,425Houston Aug. 7, 1928 1,941,597 Cavagnaro Jan. 2, 1934 1,954,349 DeweyApr. 10, 1934 2,021,560 Lira Nov. 19, 1935 2,311,451 Maurer Feb. 16,1943 2,655,098 Dutro Oct. 13, 1953 2,667,924 Dutro Feb. 2, 19542,762,255 Anderson Sept. 11, 1956 2,932,508 Tennler Apr. 12, 1960FOREIGN PATENTS 578,542 France July 5, 1924 453,163 Great Britain Sept.7, 1936

1. WEB PUNCHING MECHANISM FOR OPERATING ON A CONTINUOUSLY FED WEB, SAIDMECHANISM COMPRISING A VERTICALLY RECIPROCABLE PUNCH PRESS AND DIEREQUIRING AN INTERMITTENT WEB FEED, AND MEANS FOR ALTERNATELY STOPPINGAND ACCELERATING THAT PORTION OF THE WEB WHICH IS IN THE DIE, SAID MEANSINCLUDING A FIRST IDLER NEAR THE BOTTOM OF THE PRESS COOPERATING WITHTWO COLLATERAL SPACED DIRECTIONCHANGING ROLLERS THEREABOVE AT THE DIEHEIGHT TO FORM A GENERALLY UPRIGHT REVERSE LOOP OF WEB AHEAD OF THE DIE,SAID IDLER BEING LOCATED IN AND FORMING THE LOWER END OF THE LOOP, ASECOND SIMILAR IDLER NEAR THE BOTTOM OF THE PRESS COOPERATING WITH TWOCOLLATERAL SPACED DIRECTION-CHANGING ROLLERS THEREABOVE AT THE DIEHEIGHT TO FORM A SECOND SIMILAR GENERALLY UPRIGHT REVERSE LOOP OF WEBFOLLOWING THE DIE, THE SIDES OF THE SAID LOOPS BEING APPROXIMATELYPARALLEL, AND HAVING A VERTICAL DIMENSION WHICH IS LARGE RELATIVE TO THEECCENTRICITY IN ORDER TO MINIMIZE THE PROBLEM OF ANGULARITY AS THE LOOPIS OSCILLATED BY THE IDLER, A SHAFT CARRYING SAID FIRST IDLERECCENTRICALLY, A SHAFT CARRYING SAID SECOND IDLER ECCENTRICALLY, MEANSGEARING SAID SHAFTS TOGETHER FOR CONTINUOUS EQUAL ROTATION IN OPPOSITEPHASE SO THAT ONE LOOP IS LENGTHENED WHILE THE OTHER IS SHORTENED, SAIDIDLERS HAVING THE SAME RADIUS OF ECCENTRICITY SO SELECTED THAT THE WEBIS STOPPED AT DESIRED PITCH LENGTH, GEARING FOR DRIVING ONE OF SAIDDIRECTION-CHANGING ROLLERS AHEAD OF THE DIE AND ONE FOLLOWING THE DIE INTWOTO-ONE RATIO RELATIVE TO THE ROTATION OF THE SHAFTS CARRYING THEECCENTRIC LOOP-FORMING ROLLERS, THE SAID DRIVEN DIRECTION-CHANGINGROLLERS BEING SLIGHTLY ECCENTRICALLY MOUNTED, THE AMOUNT OF ECCENTRICITYAND THE PHASE RELATION OF THE SAID DRIVEN DIRECTION-CHANGING ROLLERSBEING SUCH AS TO COMPENSATE FOR THE ANGULARITY OF THE LOOPS CAUSEDDURING REVOLUTION OF THE ECCENTRIC LOOP-FORMING IDLERS.